What are two pathways to antibiotics contaminating the environment?

What are two pathways to antibiotics contaminating the environment?

• A. Urban; Agricultural
• B. Urban; Rural
• C. Agricultural; Industrial
• D. Domestic; Environmental

Answer: (A)

Antibiotics reach the environment mainly through waste streams linked to humans and animals. In urban settings, the drugs taken by people are excreted and enter municipal wastewater; treatment plants may not remove all residues, so some antibiotics are released into rivers or lakes, and sludge or biosolids applied to land can introduce them to soils. In agriculture, antibiotics used in livestock and poultry are also excreted and end up in manure or slurry; this waste is often spread on fields or stored in lagoons, and rainfall or irrigation can move the compounds into soil and water. Together, these two pathways—urban wastewater and agricultural manure/ runoff—are the primary routes by which antibiotics contaminate the environment. Other pathways exist but are less central to the widespread environmental presence of antibiotics.

Antibiotics reach the environment mainly through waste streams linked to humans and animals. In urban settings, the drugs taken by people are excreted and enter municipal wastewater; treatment plants may not remove all residues, so some antibiotics are released into rivers or lakes, and sludge or biosolids applied to land can introduce them to soils. In agriculture, antibiotics used in livestock and poultry are also excreted and end up in manure or slurry; this waste is often spread on fields or stored in lagoons, and rainfall or irrigation can move the compounds into soil and water. Together, these two pathways—urban wastewater and agricultural manure/ runoff—are the primary routes by which antibiotics contaminate the environment. Other pathways exist but are less central to the widespread environmental presence of antibiotics.